Safety lock



M y 8, 1957 J. I. CANNON 2,793,521

SAFETY LOCK Filed Aug. 25, 1954 United States Patent SAFETY LOCK John I.Cannon, Garden City, Pa. Application August 25, 1954, Serial No. 452,111

1 Claim. (Cl. 70-181) This invention relates to safety locks and moreparticularly to an interior safety lock for doors of automotivevehicles.

The conventional interior door lock mechanism for automobiles comprisesa generally cylindrical actuator disposed in an aperture in the doorwindow sill. This actuator is normally movable downwardly to render theconventional exterior door handle ineffectual to unlatch the door. Inthis position the actuator may be grasped and raised to a position inwhich unlatching of the door by means of the door handle is againpossible.

In some instances the device is releasable automatically when theinterior door handle is operated to unlatch the door. In other instancesthe device is effective to render both the exterior and interior doorhandles inoperative to open the door so that the door cannot be openedfrom either side until the aforesaid actuator is manually ele vated. Itis to the latter type of door latch mechanism. that the presentinvention particularly pertains.

A disadvantage of this type of actuator is that it may readily be raisedto the unlocked position by a child who may subsequently turn the doorhandle and thus open the door. Frequently children are seriously injuredby falling through the opened door and very often the automobile isdamaged in an elfort to save the child. A principal object of theinvention therefore is to provide an interior safety lock for the doorsof automobiles which may be unlocked only by a volitional act of aresponsible person.

A further object of the invention is to provide a safety lock of thestated character wherein no substantial modification of the existingdoor lock structure is required.

The invention resides further in certain structural details hereinafterdescribed and illustrated in the attached drawings wherein:

Fig. 1 is a fragmentary elevational View showing the inside ofautomobile doors and the relation of the lock actuator of the presentinvention to the conventional door unlatching mechanism;

Fig. 2 is an enlarged fragmentary elevational view partly in sectionshowing the position the actuator element assumes when the interior doorhandles are incapable of unlatching the vehicle doors;

Fig. 3 is a similarly enlarged view of the door lock actuator of thepresent invention;

Fig. 4 is a view corresponding to Fig. 2 showing the door lock actuatorin the position it assumes when the interior door handle is capable ofactuating the conventional door latching mechanism and showing also themeans by which the actuator is raised to this unl-atched position;

Fig. 5 is :a sectional view taken substantially on line 55 of Fig. 4;

Fig. 6 is a view in perspective of a tool for raising the actuator tothe position shown in Fig. 4; and

Fig. 7 is a perspective view in vertical section of the actuator.

With reference to the drawing and more particularly to 2. Figs. 2 and 4,the embodiment of the invention therein disclosed comprises a manuallydisplaceable body member 10 which is designed to replace theconventionalautomobile door lock actuator of the type shown at 11. InFig. 4 the element 10 is shown in elevated or latch release position.When the element is moved downwardly as shown in Fig. 2 the shaft 12causes the bell crank 13 to pivot about the axis 14 to render both theexterior door handle (not shown) and the interior door handle 15inoperative to actuate the door latching mechanism 16.

In accordance with the present invention the body member 10 isdimensioned so as to lie substantially flush with the sill of thevehicle window when in the depressed or safety position wherein theinterior handle 15 is inoperative as described. In this position it ismanifestly impossible to grasp the body member with the fingers and thedoor cannot be unlocked from the inside without the use of a specialtool hereafter described for elevating the said member. This is indirect contrast with conventional locking devices of the type shown at11 in Fig. l where the actuating element still remains in positionreadily accessible for finger operation when in the depressed or latchlocking position.

As shown in Figs. 2, 3, 4, 5, and 7, the body member is provided with alongitudinal slot 17 terminating in a generally cylindrical cavity 18 ofgreater diameter than the narrow cross-section of the slot, thus formingshoulders 20 and 21. This slot is designed to receive a key 19 having awing 22 projecting outwardly from each side of the shaft portion 23. Theshaft of the key is dimensioned so as to be capable of rotation in theslot, while the wings can be turned only when received in the cavity 18.When the key is turned in this manner it interlocks with the body memberto afford :a finger grip for displacement of the member to the positionshown in Fig. 4.

In operation, the key is inserted in the slot so that the wings arereceived in the cavity 18. The key is then rotated to the position shownin Fig. 4 wherein the wings underlie the shoulders 20 and 21. The key isthen drawn upwardly, thus pulling the body member and the shaft 12upwardly so that the handle 15 again becomes operative to unlatch thedoor.

As shown in Fig. 2, a threaded aperture 33 in the body member receivesthe correspondingly threaded upper end of the shaft 12. Passage of thetool into the slot 17 may be facilitated by chamfering the edges of theslot, as at 34.

The above-described device is capable of locking a vehicle door so thatthe vehicle operator is free to devote his full attention to operationof the vehicle without fear that juvenile passengers will inadvertentlyopen a door and thereby become injured. The lock of the presentinvention requires no modification of existing structure other than thesimple removal of the conventional door lock actuator and substitutionof the improved actuator described above. The device is economical ofmanufacture and lends itself readily to production by relatively simplecasting or molding operation, or by fabrication from sheet metal. Ifmade of hard rubber or other material in which the stern 12 would beself-threading, the device would have a universal application regardlessof the type of threading on the rod and in such case, the bore forreception of the rod would be unthreaded.

Iclaim:

In an automobile door safety lock of the type comprising a buttonactuator projecting through an aperture in the door structure anddisplaceable inwardly to immobilize the door latching mechanism and,outwardly to release the latch, the improvement which consists in therelative arrangement of elements whereby the outer end of said buttonwhen the latter is in the inwardly displaced and door latch immobilizingposition lies within the said aperture so that the outer end surface ofthe button conlatter is inaccessible to the fingers for subsequentdisplacement outwardly to the latch release position, said button havinga-socket opening to said outer end surface and containing'an undercutshoulder, and an instrument adapted for insertion in said socket andfrom the said end surface and having a lateral projection for engagementunder said shoulder so as to provide a means for applying a manualwithdrawing force to the button to displace the latter to the latchrelease position.

References Cited in the file of this patent UNITED STATES PATENTS

